[PATCH 07/27] ext4: refactor ext4_insert_range()

Zhang Yi
2024-10-22T03:13:02Z

From: Zhang Yi <yi.zhang@huawei.com>

Simplify ext4_insert_range() and align its code style with that of
ext4_collapse_range(). Refactor it by: a) renaming variables, b)
removing redundant input parameter checks and moving the remaining
checks under i_rwsem in preparation for future refactoring, and c)
renaming the three stale error tags.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
fs/ext4/extents.c | 101 ++++++++++++++++++++++------------------------
1 file changed, 48 insertions(+), 53 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a4e95f3b5f09..4e35c2415e9b 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5428,45 +5428,37 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
handle_t *handle;
struct ext4_ext_path *path;
struct ext4_extent *extent;
- ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
+ ext4_lblk_t start_lblk, len_lblk, ee_start_lblk = 0;
unsigned int credits, ee_len;
- int ret = 0, depth, split_flag = 0;
- loff_t ioffset;
-
- /*
- * We need to test this early because xfstests assumes that an
- * insert range of (0, 1) will return EOPNOTSUPP if the file
- * system does not support insert range.
- */
- if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
- return -EOPNOTSUPP;
-
- /* Insert range works only on fs cluster size aligned regions. */
- if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
- return -EINVAL;
+ int ret, depth, split_flag = 0;
+ loff_t start;

trace_ext4_insert_range(inode, offset, len);

- offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
- len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
-
inode_lock(inode);
+
/* Currently just for extent based files */
if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
ret = -EOPNOTSUPP;
- goto out_mutex;
+ goto out;
}

- /* Check whether the maximum file size would be exceeded */
- if (len > inode->i_sb->s_maxbytes - inode->i_size) {
- ret = -EFBIG;
- goto out_mutex;
+ /* Insert range works only on fs cluster size aligned regions. */
+ if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
+ ret = -EINVAL;
+ goto out;
}

/* Offset must be less than i_size */
if (offset >= inode->i_size) {
ret = -EINVAL;
- goto out_mutex;
+ goto out;
+ }
+
+ /* Check whether the maximum file size would be exceeded */
+ if (len > inode->i_sb->s_maxbytes - inode->i_size) {
+ ret = -EFBIG;
+ goto out;
}

/* Wait for existing dio to complete */
@@ -5474,7 +5466,7 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)

ret = file_modified(file);
if (ret)
- goto out_mutex;
+ goto out;

/*
* Prevent page faults from reinstantiating pages we have released from
@@ -5484,25 +5476,24 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)

ret = ext4_break_layouts(inode);
if (ret)
- goto out_mmap;
+ goto out_invalidate_lock;

/*
- * Need to round down to align start offset to page size boundary
- * for page size > block size.
+ * Write out all dirty pages. Need to round down to align start offset
+ * to page size boundary for page size > block size.
*/
- ioffset = round_down(offset, PAGE_SIZE);
- /* Write out all dirty pages */
- ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
- LLONG_MAX);
+ start = round_down(offset, PAGE_SIZE);
+ ret = filemap_write_and_wait_range(mapping, start, LLONG_MAX);
if (ret)
- goto out_mmap;
- truncate_pagecache(inode, ioffset);
+ goto out_invalidate_lock;
+
+ truncate_pagecache(inode, start);

credits = ext4_writepage_trans_blocks(inode);
handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
- goto out_mmap;
+ goto out_invalidate_lock;
}
ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);

@@ -5511,16 +5502,19 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
EXT4_I(inode)->i_disksize += len;
ret = ext4_mark_inode_dirty(handle, inode);
if (ret)
- goto out_stop;
+ goto out_handle;
+
+ start_lblk = offset >> inode->i_blkbits;
+ len_lblk = len >> inode->i_blkbits;

down_write(&EXT4_I(inode)->i_data_sem);
ext4_discard_preallocations(inode);

- path = ext4_find_extent(inode, offset_lblk, NULL, 0);
+ path = ext4_find_extent(inode, start_lblk, NULL, 0);
if (IS_ERR(path)) {
up_write(&EXT4_I(inode)->i_data_sem);
ret = PTR_ERR(path);
- goto out_stop;
+ goto out_handle;
}

depth = ext_depth(inode);
@@ -5530,16 +5524,16 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
ee_len = ext4_ext_get_actual_len(extent);

/*
- * If offset_lblk is not the starting block of extent, split
- * the extent @offset_lblk
+ * If start_lblk is not the starting block of extent, split
+ * the extent @start_lblk
*/
- if ((offset_lblk > ee_start_lblk) &&
- (offset_lblk < (ee_start_lblk + ee_len))) {
+ if ((start_lblk > ee_start_lblk) &&
+ (start_lblk < (ee_start_lblk + ee_len))) {
if (ext4_ext_is_unwritten(extent))
split_flag = EXT4_EXT_MARK_UNWRIT1 |
EXT4_EXT_MARK_UNWRIT2;
path = ext4_split_extent_at(handle, inode, path,
- offset_lblk, split_flag,
+ start_lblk, split_flag,
EXT4_EX_NOCACHE |
EXT4_GET_BLOCKS_PRE_IO |
EXT4_GET_BLOCKS_METADATA_NOFAIL);
@@ -5548,31 +5542,32 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
if (IS_ERR(path)) {
up_write(&EXT4_I(inode)->i_data_sem);
ret = PTR_ERR(path);
- goto out_stop;
+ goto out_handle;
}
}

ext4_free_ext_path(path);
- ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);
+ ext4_es_remove_extent(inode, start_lblk, EXT_MAX_BLOCKS - start_lblk);

/*
- * if offset_lblk lies in a hole which is at start of file, use
+ * if start_lblk lies in a hole which is at start of file, use
* ee_start_lblk to shift extents
*/
ret = ext4_ext_shift_extents(inode, handle,
- max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT);
-
+ max(ee_start_lblk, start_lblk), len_lblk, SHIFT_RIGHT);
up_write(&EXT4_I(inode)->i_data_sem);
+ if (ret)
+ goto out_handle;
+
+ ext4_update_inode_fsync_trans(handle, inode, 1);
if (IS_SYNC(inode))
ext4_handle_sync(handle);
- if (ret >= 0)
- ext4_update_inode_fsync_trans(handle, inode, 1);

-out_stop:
+out_handle:
ext4_journal_stop(handle);
-out_mmap:
+out_invalidate_lock:
filemap_invalidate_unlock(mapping);
-out_mutex:
+out:
inode_unlock(inode);
return ret;
}
--
2.46.1